The present invention relates to textile winding bobbin driving systems, and more particularly, to an apparatus for automatically switching off and disconnecting an electric motor shaft drive which accelerates a winding bobbin and automatically substituting for the shaft drive a synchronized circumferential cylinder drive which engages the winding bobbin as the diameter of the bobbin increases with textiles spun thereon.
Circumferential drives with driving cylinders are very frequently used for spinning the winding bobbins in the chemical fiber industry, since constant thread withdrawal velocities can be maintained relatively easily thereby. These circumferential drives are not always capable of accelerating the empty winding bobbin from standstill to the nominal speed in a relatively short time, however. Therefore, additional shaft drives are utilized which are disconnected once the circumferential cylinder drive has become effective. The change in the torque supplied by the shaft-drive motor due to the activation of the circumferential cylinder drive motor can then be used as a measure of the time at which the shaft drive should be disconnected and turned off. The problem arises, however, that the torque corresponding to the time when the shaft drive motor should be disconnected depends on numerous parameters such as the number of threads to be wound simultaneously, the thread thickness, the thread velocity and the air gap between the bobbin and the driving cylinder.
Accordingly, it is an object of the present invention to provide an apparatus which will automatically disconnect the shaft drive at the proper time dependent on the numerous parameters which affect torque requirements.